Various types of telescoping outriggers have been proposed for stabilizing mobile cranes against tipping when its extensible load carrying boom is swung to various working positions. Hydraulic means have been proposed for providing the power for telescoping the outrigger sections relative to one another and such arrangements are shown in the U.S. Pat. No. 4,124,226 issued Nov. 7, 1978 to Phillips and is assigned to an assignee common with the present invention.
Some prior devices have had shortcomings because of their considerable weight and complexity, both in design and maintenance. Furthermore, some prior art devices were difficult to service, particularly when the hydraulic system was subject to leaking. Some prior outrigger devices would also shift or give slightly when subjected to concentrated compressive loads.